Wireless network communication nodes with opt out capability

ABSTRACT

Techniques are disclosed herein for providing wireless network communication nodes with opt-out capabilities. Such capabilities may, for example, allow particular customers to opt out of a typical full-scale communication mode such that their associated equipment operates at least temporarily in a limited communication mode. The limited communication mode may limit customer exposure to emissions resulting from RF communications near their homes or other areas, which may be attractive to customers such as those with health or other emission-related concerns.

TECHNICAL BACKGROUND

The reading of electrical energy, water flow, and gas usage hashistorically been accomplished with human meter readers who came on-siteand manually documented meter readings. Over time, this manual meterreading methodology has been enhanced with walk by or drive by readingsystems that use radio communications to and from a mobile collectordevice in a vehicle. Recently, there has been a concerted effort toaccomplish meter reading using fixed communication networks that allowdata to flow from the meter to a host computer system without humanintervention.

Automated systems, such as Automatic Meter Reading (AMR) and AdvancedMetering Infrastructure (AMI) systems, collect data from meters thatmeasure usage of resources, such as gas, water and electricity. Suchsystems may employ a number of different infrastructures for collectingthis meter data from the meters. For example, some automated systemsobtain data from the meters using a fixed wireless network thatincludes, for example, a central node, e.g., a collection device, incommunication with a number of endpoint nodes (e.g., meter readingdevices (MRDs) connected to meters). At the endpoint nodes, the wirelesscommunications circuitry may be incorporated into the meters themselves,such that each endpoint node in the wireless network comprises a meterconnected to an MRD that has wireless communication circuitry thatenables the MRD to transmit the meter data of the meter to which it isconnected. The wireless communication circuitry may include atransponder that is uniquely identified by a transponder serial number.The endpoint nodes may either transmit their meter data directly to thecentral node, or indirectly though one or more intermediatebi-directional nodes that serve as repeaters for the meter data of thetransmitting node.

Some networks may employ a mesh networking architecture. In suchnetworks, known as “mesh networks,” endpoint nodes are connected to oneanother through wireless communication links such that each endpointnode has a wireless communication path to the central node. Onecharacteristic of mesh networks is that the component nodes can allconnect to one another via one or more “hops.” Due to thischaracteristic, mesh networks can continue to operate even if a node ora connection breaks down. Accordingly, mesh networks areself-configuring and self-healing, significantly reducing installationand maintenance efforts.

There is a perception among some utility and metering consumers thatprolonged exposure to even low levels of radio frequency (RF)communications emissions may possibly be damaging to health. There isalso a perception that certain individuals may be particularly sensitiveto RF transmissions and that such individuals may experience headachesand other discomforts. With the large scale deployments of electricitymeters that incorporate radios for the communication of usage data,outage information and other status data, this segment of consumers maydesire the to limit RF communications occurring near their homes. Somepublic utility commissions may also be making similar requests ofutilities to limit RF communications. Typically, this has resulted ininstalling a dial up hard line modem in a meter or resorting to atraditional manual on-site meter reading method.

SUMMARY OF THE DISCLOSURE

Techniques are disclosed herein for providing wireless networkcommunication nodes with opt-out capabilities. Such capabilities may,for example, allow particular customers to opt out of a full-scalecommunication mode such that their associated equipment operates atleast temporarily in a limited communication mode. The limitedcommunication mode may limit customer exposure to emissions resultingfrom RF communications near their homes or other areas, which may beattractive to customers such as those with health or otheremission-related concerns.

Nodes operating in the limited communication mode may be configured in anumber of ways in order to limit their associated RF communications. Forexample, limited communication mode nodes may be configured such thatthey are restricted from serving as repeaters within the wirelessnetwork. Limited communication mode nodes may also be configured totransmit their associated data less frequently than other communicationnodes. Furthermore, various techniques may be employed to help ensurethat one or more reliable communication paths are retained for a limitedcommunication mode node during periods when the node is not transmittingits associated data.

In some cases, to limit RF communications emissions, a limitedcommunication mode node's transceiver may be powered off during periodswhen the node isn't transmitting its associated data. In other cases, alimited communication mode node's transceiver may remain powered on sothat the node may remain capable of receiving necessary network or otherinformation. Limited communication mode nodes may also be configuredsuch that they are permitted to send only certain types of messagesand/or to respond to only certain types of requests.

Other features and advantages of the described embodiments may becomeapparent from the following detailed description and accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing summary, as well as the following detailed description ofvarious embodiments, is better understood when read in conjunction withthe appended drawings. For the purpose of illustrating the invention,there are shown in the drawings exemplary embodiments of various aspectsof the invention; however, the invention is not limited to the specificmethods and instrumentalities disclosed. In the drawings:

FIG. 1 is a diagram of an exemplary metering system;

FIG. 2 expands upon the diagram of FIG. 1 and illustrates an exemplarymetering system in greater detail;

FIG. 3A is a block diagram illustrating an exemplary collector;

FIG. 3B is a block diagram illustrating an exemplary meter;

FIG. 4 is a diagram of an exemplary subnet of a wireless network forcollecting data from remote devices;

FIGS. 5A and 5B depict an example scenario in which a repeater node isswitched from operation in a full-scale communication mode to operationin a limited communication mode; and

FIG. 6 depicts a flowchart of an example limited communication nodeconfiguration process.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Exemplary systems and methods for gathering meter data are describedbelow with reference to FIGS. 1-6. It will be appreciated by those ofordinary skill in the art that the description given herein with respectto those figures is for exemplary purposes only and is not intended inany way to limit the scope of potential embodiments.

Generally, a plurality of meter devices, which operate to track usage ofa service or commodity such as, for example, electricity, water, andgas, are operable to wirelessly communicate. One or more devices,referred to herein as “collectors,” are provided that “collect” datatransmitted by the other meter devices so that it can be accessed byother computer systems. The collectors receive and compile metering datafrom a plurality of meter devices via wireless communications. A datacollection server may communicate with the collectors to retrieve thecompiled meter data.

FIG. 1 provides a diagram of one exemplary metering system 110. System110 comprises a plurality of meters 114, which are operable to sense andrecord consumption or usage of a service or commodity such as, forexample, electricity, water, or gas. Meters 114 may be located atcustomer premises such as, for example, a home or place of business.Meters 114 comprise circuitry for measuring the consumption of theservice or commodity being consumed at their respective locations andfor generating data reflecting the consumption, as well as other datarelated thereto. Meters 114 may also comprise circuitry for wirelesslytransmitting data generated by the meter to a remote location. Meters114 may further comprise circuitry for receiving data, commands orinstructions wirelessly as well. Meters that are operable to bothreceive and transmit data may be referred to as “bi-directional” or“two-way” meters, while meters that are only capable of transmittingdata may be referred to as “transmit-only” or “one-way” meters. Inbi-directional meters, the circuitry for transmitting and receiving maycomprise a transceiver. In an illustrative embodiment, meters 114 maybe, for example, electricity meters manufactured by Elster Solutions,LLC and marketed under the tradename REX.

System 110 further comprises collectors 116. In one embodiment,collectors 116 are also meters operable to detect and record usage of aservice or commodity such as, for example, electricity, water, or gas.In addition, collectors 116 are operable to send data to and receivedata from meters 114. Thus, like the meters 114, the collectors 116 maycomprise both circuitry for measuring the consumption of a service orcommodity and for generating data reflecting the consumption andcircuitry for transmitting and receiving data. In one embodiment,collector 116 and meters 114 communicate with and amongst one anotherusing any one of several wireless techniques such as, for example,frequency hopping spread spectrum (FHSS) and direct sequence spreadspectrum (DSSS).

A collector 116 and the meters 114 with which it communicates define asubnet/LAN 120 of system 110. As used herein, meters 114 and collectors116 may be referred to as “nodes” in the subnet 120. In each subnet/LAN120, each meter transmits data related to consumption of the commoditybeing metered at the meter's location. The collector 116 receives thedata transmitted by each meter 114, effectively “collecting” it, andthen periodically transmits the data from all of the meters in thesubnet/LAN 120 to a data collection server 206. The data collectionserver 206 stores the data for analysis and preparation of bills, forexample. The data collection server 206 may be a specially programmedgeneral purpose computing system and may communicate with collectors 116via a network 112. The network 112 may comprise any form of network,including a wireless network or a fixed-wire network, such as a localarea network (LAN), a wide area network, the Internet, an intranet, atelephone network, such as the public switched telephone network (PSTN),a Frequency Hopping Spread Spectrum (FHSS) radio network, a meshnetwork, a Wi-Fi (802.11) network, a Wi-Max (802.16) network, a landline (POTS) network, or any combination of the above.

Referring now to FIG. 2, further details of the metering system 110 areshown. Typically, the system will be operated by a utility company or acompany providing information technology services to a utility company.As shown, the system 110 comprises a network management server 202, anetwork management system (NMS) 204 and the data collection server 206that together manage one or more subnets/LANs 120 and their constituentnodes. The NMS 204 tracks changes in network state, such as new nodesregistering/unregistering with the system 110, node communication pathschanging, etc. This information is collected for each subnet/LAN 120 andis detected and forwarded to the network management server 202 and datacollection server 206.

Each of the meters 114 and collectors 116 is assigned an identifier (LANID) that uniquely identifies that meter or collector on its subnet/LAN120. In this embodiment, communication between nodes (i.e., thecollectors and meters) and the system 110 is accomplished using the LANID. However, it is preferable for operators of a utility to query andcommunicate with the nodes using their own identifiers. To this end, amarriage file 208 may be used to correlate a utility's identifier for anode (e.g., a utility serial number) with both a manufacturer serialnumber (i.e., a serial number assigned by the manufacturer of the meter)and the LAN ID for each node in the subnet/LAN 120. In this manner, theutility can refer to the meters and collectors by the utilitiesidentifier, while the system can employ the LAN ID for the purpose ofdesignating particular meters during system communications.

A device configuration database 210 stores configuration informationregarding the nodes. For example, in the metering system 200, the deviceconfiguration database may include data regarding time of use (TOU)switchpoints, etc. for the meters 114 and collectors 116 communicatingin the system 110. A data collection requirements database 212 containsinformation regarding the data to be collected on a per node basis. Forexample, a utility may specify that metering data such as load profile,demand, TOU, etc. is to be collected from particular meter(s) 114 a.Reports 214 containing information on the network configuration may beautomatically generated or in accordance with a utility request.

The network management system (NMS) 204 maintains a database describingthe current state of the global fixed network system (current networkstate 220) and a database describing the historical state of the system(historical network state 222). The current network state 220 containsdata regarding current meter-to-collector assignments, etc. for eachsubnet/LAN 120. The historical network state 222 is a database fromwhich the state of the network at a particular point in the past can bereconstructed. The NMS 204 is responsible for, amongst other things,providing reports 214 about the state of the network. The NMS 204 may beaccessed via an API 220 that is exposed to a user interface 216 and aCustomer Information System (CIS) 218. Other external interfaces mayalso be implemented. In addition, the data collection requirementsstored in the database 212 may be set via the user interface 216 or CIS218.

The data collection server 206 collects data from the nodes (e.g.,collectors 116) and stores the data in a database 224. The data includesmetering information, such as energy consumption and may be used forbilling purposes, etc. by a utility provider.

The network management server 202, network management system 204 anddata collection server 206 communicate with the nodes in each subnet/LAN120 via network 110.

FIG. 3A is a block diagram illustrating further details of oneembodiment of a collector 116. Although certain components aredesignated and discussed with reference to FIG. 3A, it should beappreciated that the invention is not limited to such components. Infact, various other components typically found in an electronic metermay be a part of collector 116, but have not been shown in FIG. 3A forthe purposes of clarity and brevity. Also, the invention may use othercomponents to accomplish the operation of collector 116. The componentsthat are shown and the functionality described for collector 116 areprovided as examples, and are not meant to be exclusive of othercomponents or other functionality.

As shown in FIG. 3A, collector 116 may comprise metering circuitry 304that performs measurement of consumption of a service or commodity and aprocessor 305 that controls the overall operation of the meteringfunctions of the collector 116. The collector 116 may further comprise adisplay 310 for displaying information such as measured quantities andmeter status and a memory 312 for storing data. The collector 116further comprises wireless LAN communications circuitry 306 forcommunicating wirelessly with the meters 114 in a subnet/LAN and anetwork interface 308 for communication over the network 112.

In one embodiment, the metering circuitry 304, processor 305, display310 and memory 312 are implemented using an A3 ALPHA meter availablefrom Elster Electricity, Inc. In that embodiment, the wireless LANcommunications circuitry 306 may be implemented by a LAN Option Board(e.g., a 900 MHz two-way radio) installed within the A3 ALPHA meter, andthe network interface 308 may be implemented by a WAN Option Board(e.g., a telephone modem) also installed within the A3 ALPHA meter. Inthis embodiment, the WAN Option Board 308 routes messages from network112 (via interface port 302) to either the meter processor 305 or theLAN Option Board 306. LAN Option Board 306 may use a transceiver (notshown), for example a 900 MHz radio, to communicate data to meters 114.Also, LAN Option Board 306 may have sufficient memory to store datareceived from meters 114. This data may include, but is not limited tothe following: current billing data (e.g., the present values stored anddisplayed by meters 114), previous billing period data, previous seasondata, and load profile data.

LAN Option Board 306 may be capable of synchronizing its time to a realtime clock (not shown) in A3 ALPHA meter, thereby synchronizing the LANreference time to the time in the meter. The processing necessary tocarry out the communication functionality and the collection and storageof metering data of the collector 116 may be handled by the processor305 and/or additional processors (not shown) in the LAN Option Board 306and the WAN Option Board 308.

The responsibility of a collector 116 is wide and varied. Generally,collector 116 is responsible for managing, processing and routing datacommunicated between the collector and network 112 and between thecollector and meters 114. Collector 116 may continually orintermittently read the current data from meters 114 and store the datain a database (not shown) in collector 116. Such current data mayinclude but is not limited to the total kWh usage, the Time-Of-Use (TOU)kWh usage, peak kW demand, and other energy consumption measurements andstatus information. Collector 116 also may read and store previousbilling and previous season data from meters 114 and store the data inthe database in collector 116. The database may be implemented as one ormore tables of data within the collector 116.

FIG. 3B is a block diagram of an exemplary embodiment of a meter 114that may operate in the system 110 of FIGS. 1 and 2. As shown, the meter114 comprises metering circuitry 304′ for measuring the amount of aservice or commodity that is consumed, a processor 305′ that controlsthe overall functions of the meter, a display 310′ for displaying meterdata and status information, and a memory 312′ for storing data andprogram instructions. The meter 114 further comprises wirelesscommunications circuitry 306′ for transmitting and receiving datato/from other meters 114 or a collector 116.

Referring again to FIG. 1, in the exemplary embodiment shown, acollector 116 directly communicates with only a subset of the pluralityof meters 114 in its particular subnet/LAN. Meters 114 with whichcollector 116 directly communicates may be referred to as “level one”meters 114 a. The level one meters 114 a are said to be one “hop” fromthe collector 116. Communications between collector 116 and meters 114other than level one meters 114 a are relayed through the level onemeters 114 a. Thus, the level one meters 114 a operate as repeaters forcommunications between collector 116 and meters 114 located further awayin subnet 120.

Each level one meter 114 a typically will only be in range to directlycommunicate with only a subset of the remaining meters 114 in the subnet120. The meters 114 with which the level one meters 114 a directlycommunicate may be referred to as level two meters 114 b. Level twometers 114 b are one “hop” from level one meters 114 a, and thereforetwo “hops” from collector 116. Level two meters 114 b operate asrepeaters for communications between the level one meters 114 a andmeters 114 located further away from collector 116 in the subnet 120.

While only three levels of meters are shown (collector 116, first level114 a, second level 114 b) in FIG. 1, a subnet 120 may comprise anynumber of levels of meters 114. For example, a subnet 120 may compriseone level of meters but might also comprise eight or more levels ofmeters 114. In an embodiment wherein a subnet comprises eight levels ofmeters 114, as many as 1024 meters might be registered with a singlecollector 116.

As mentioned above, each meter 114 and collector 116 that is installedin the system 110 has a unique identifier (LAN ID) stored thereon thatuniquely identifies the device from all other devices in the system 110.Additionally, meters 114 operating in a subnet 120 comprise informationincluding the following: data identifying the collector with which themeter is registered; the level in the subnet at which the meter islocated; the repeater meter at the prior level with which the metercommunicates to send and receive data to/from the collector; anidentifier indicating whether the meter is a repeater for other nodes inthe subnet; and if the meter operates as a repeater, the identifier thatuniquely identifies the repeater within the particular subnet, and thenumber of meters for which it is a repeater. Collectors 116 have storedthereon all of this same data for all meters 114 that are registeredtherewith. Thus, collector 116 comprises data identifying all nodesregistered therewith as well as data identifying the registered path bywhich data is communicated from the collector to each node. Each meter114 therefore has a designated communications path to the collector thatis either a direct path (e.g., all level one nodes) or an indirect paththrough one or more intermediate nodes that serve as repeaters.

Information is transmitted in this embodiment in the form of packets.For most network tasks such as, for example, reading meter data,collector 116 communicates with meters 114 in the subnet 120 usingpoint-to-point transmissions. For example, a message or instruction fromcollector 116 is routed through the designated set of repeaters to thedesired meter 114. Similarly, a meter 114 communicates with collector116 through the same set of repeaters, but in reverse.

In some instances, however, collector 116 may need to quicklycommunicate information to all meters 114 located in its subnet 120.Accordingly, collector 116 may issue a broadcast message that is meantto reach all nodes in the subnet 120. The broadcast message may bereferred to as a “flood broadcast message.” A flood broadcast originatesat collector 116 and propagates through the entire subnet 120 one levelat a time. For example, collector 116 may transmit a flood broadcast toall first level meters 114 a. The first level meters 114 a that receivethe message pick a random time slot and retransmit the broadcast messageto second level meters 114 b. Any second level meter 114 b can acceptthe broadcast, thereby providing better coverage from the collector outto the end point meters. Similarly, the second level meters 114 b thatreceive the broadcast message pick a random time slot and communicatethe broadcast message to third level meters. This process continues outuntil the end nodes of the subnet. Thus, a broadcast message graduallypropagates outward from the collector to the nodes of the subnet 120.

The flood broadcast packet header contains information to prevent nodesfrom repeating the flood broadcast packet more than once per level. Forexample, within a flood broadcast message, a field might exist thatindicates to meters/nodes which receive the message, the level of thesubnet the message is located; only nodes at that particular level mayre-broadcast the message to the next level. If the collector broadcastsa flood message with a level of 1, only level 1 nodes may respond. Priorto re-broadcasting the flood message, the level 1 nodes increment thefield to 2 so that only level 2 nodes respond to the broadcast.Information within the flood broadcast packet header ensures that aflood broadcast will eventually die out.

Generally, a collector 116 issues a flood broadcast several times, e.g.five times, successively to increase the probability that all meters inthe subnet 120 receive the broadcast. A delay is introduced before eachnew broadcast to allow the previous broadcast packet time to propagatethrough all levels of the subnet.

Meters 114 may have a clock formed therein. However, meters 114 oftenundergo power interruptions that can interfere with the operation of anyclock therein. Accordingly, the clocks internal to meters 114 cannot berelied upon to provide an accurate time reading. Having the correct timeis necessary, however, when time of use metering is being employed.Indeed, in an embodiment, time of use schedule data may also becomprised in the same broadcast message as the time. Accordingly,collector 116 periodically flood broadcasts the real time to meters 114in subnet 120. Meters 114 use the time broadcasts to stay synchronizedwith the rest of the subnet 120. In an illustrative embodiment,collector 116 broadcasts the time every 15 minutes. The broadcasts maybe made near the middle of 15 minute clock boundaries that are used inperforming load profiling and time of use (TOU) schedules so as tominimize time changes near these boundaries. Maintaining timesynchronization is important to the proper operation of the subnet 120.Accordingly, lower priority tasks performed by collector 116 may bedelayed while the time broadcasts are performed.

In an illustrative embodiment, the flood broadcasts transmitting timedata may be repeated, for example, five times, so as to increase theprobability that all nodes receive the time. Furthermore, where time ofuse schedule data is communicated in the same transmission as the timingdata, the subsequent time transmissions allow a different piece of thetime of use schedule to be transmitted to the nodes.

Exception messages are used in subnet 120 to transmit unexpected eventsthat occur at meters 114 to collector 116. In an embodiment, the first 4seconds of every 32-second period are allocated as an exception windowfor meters 114 to transmit exception messages. Meters 114 transmit theirexception messages early enough in the exception window so the messagehas time to propagate to collector 116 before the end of the exceptionwindow. Collector 116 may process the exceptions after the 4-secondexception window. Generally, a collector 116 acknowledges exceptionmessages, and collector 116 waits until the end of the exception windowto send this acknowledgement.

In an illustrative embodiment, exception messages are configured as oneof three different types of exception messages: local exceptions, whichare handled directly by the collector 116 without intervention from datacollection server 206; an immediate exception, which is generallyrelayed to data collection server 206 under an expedited schedule; and adaily exception, which is communicated to the communication server 122on a regular schedule.

Exceptions are processed as follows. When an exception is received atcollector 116, the collector 116 identifies the type of exception thathas been received. If a local exception has been received, collector 116takes an action to remedy the problem. For example, when collector 116receives an exception requesting a “node scan request” such as discussedbelow, collector 116 transmits a command to initiate a scan procedure tothe meter 114 from which the exception was received.

If an immediate exception type has been received, collector 116 makes arecord of the exception. An immediate exception might identify, forexample, that there has been a power outage. Collector 116 may log thereceipt of the exception in one or more tables or files. In anillustrative example, a record of receipt of an immediate exception ismade in a table referred to as the “Immediate Exception Log Table.”Collector 116 then waits a set period of time before taking furtheraction with respect to the immediate exception. For example, collector116 may wait 64 seconds. This delay period allows the exception to becorrected before communicating the exception to the data collectionserver 206. For example, where a power outage was the cause of theimmediate exception, collector 116 may wait a set period of time toallow for receipt of a message indicating the power outage has beencorrected.

If the exception has not been corrected, collector 116 communicates theimmediate exception to data collection server 206. For example,collector 116 may initiate a dial-up connection with data collectionserver 206 and download the exception data. After reporting an immediateexception to data collection server 206, collector 116 may delayreporting any additional immediate exceptions for a period of time suchas ten minutes. This is to avoid reporting exceptions from other meters114 that relate to, or have the same cause as, the exception that wasjust reported.

If a daily exception was received, the exception is recorded in a fileor a database table. Generally, daily exceptions are occurrences in thesubnet 120 that need to be reported to data collection server 206, butare not so urgent that they need to be communicated immediately. Forexample, when collector 116 registers a new meter 114 in subnet 120,collector 116 records a daily exception identifying that theregistration has taken place. In an illustrative embodiment, theexception is recorded in a database table referred to as the “DailyException Log Table.” Collector 116 communicates the daily exceptions todata collection server 206. Generally, collector 116 communicates thedaily exceptions once every 24 hours.

In the present embodiment, a collector assigns designated communicationspaths to meters with bi-directional communication capability, and maychange the communication paths for previously registered meters ifconditions warrant. For example, when a collector 116 is initiallybrought into system 110, it needs to identify and register meters in itssubnet 120. A “node scan” refers to a process of communication between acollector 116 and meters 114 whereby the collector may identify andregister new nodes in a subnet 120 and allow previously registered nodesto switch paths. A collector 116 can implement a node scan on the entiresubnet, referred to as a “full node scan,” or a node scan can beperformed on specially identified nodes, referred to as a “node scanretry.”

A full node scan may be performed, for example, when a collector isfirst installed. The collector 116 must identify and register nodes fromwhich it will collect usage data. The collector 116 initiates a nodescan by broadcasting a request, which may be referred to as a Node ScanProcedure request. Generally, the Node Scan Procedure request directsthat all unregistered meters 114 or nodes that receive the requestrespond to the collector 116. The request may comprise information suchas the unique address of the collector that initiated the procedure. Thesignal by which collector 116 transmits this request may have limitedstrength and therefore is detected only at meters 114 that are inproximity of collector 116. Meters 114 that receive the Node ScanProcedure request respond by transmitting their unique identifier aswell as other data.

For each meter from which the collector receives a response to the NodeScan Procedure request, the collector tries to qualify thecommunications path to that meter before registering the meter with thecollector. That is, before registering a meter, the collector 116attempts to determine whether data communications with the meter will besufficiently reliable. In one embodiment, the collector 116 determineswhether the communication path to a responding meter is sufficientlyreliable by comparing a Received Signal Strength Indication (RSSI) value(i.e., a measurement of the received radio signal strength) measuredwith respect to the received response from the meter to a selectedthreshold value. For example, the threshold value may be −60 dBm. RSSIvalues above this threshold would be deemed sufficiently reliable. Inanother embodiment, qualification is performed by transmitting apredetermined number of additional packets to the meter, such as tenpackets, and counting the number of acknowledgements received back fromthe meter. If the number of acknowledgments received is greater than orequal to a selected threshold (e.g., 8 out of 10), then the path isconsidered to be reliable. In other embodiments, a combination of thetwo qualification techniques may be employed.

If the qualification threshold is not met, the collector 116 may add anentry for the meter to a “Straggler Table.” The entry includes themeter's LAN ID, its qualification score (e.g., 5 out of 10; or its RSSIvalue), its level (in this case level one) and the unique ID of itsparent (in this case the collector's ID).

If the qualification threshold is met or exceeded, the collector 116registers the node. Registering a meter 114 comprises updating a list ofthe registered nodes at collector 116. For example, the list may beupdated to identify the meter's system-wide unique identifier and thecommunication path to the node. Collector 116 also records the meter'slevel in the subnet (i.e. whether the meter is a level one node, leveltwo node, etc.), whether the node operates as a repeater, and if so, thenumber of meters for which it operates as a repeater. The registrationprocess further comprises transmitting registration information to themeter 114. For example, collector 116 forwards to meter 114 anindication that it is registered, the unique identifier of the collectorwith which it is registered, the level the meter exists at in thesubnet, and the unique identifier of its parent meter that will serveras a repeater for messages the meter may send to the collector. In thecase of a level one node, the parent is the collector itself. The meterstores this data and begins to operate as part of the subnet byresponding to commands from its collector 116.

Qualification and registration continues for each meter that responds tothe collector's initial Node Scan Procedure request. The collector 116may rebroadcast the Node Scan Procedure additional times so as to insurethat all meters 114 that may receive the Node Scan Procedure have anopportunity for their response to be received and the meter qualified asa level one node at collector 116.

The node scan process then continues by performing a similar process asthat described above at each of the now registered level one nodes. Thisprocess results in the identification and registration of level twonodes. After the level two nodes are identified, a similar node scanprocess is performed at the level two nodes to identify level threenodes, and so on.

Specifically, to identify and register meters that will become level twometers, for each level one meter, in succession, the collector 116transmits a command to the level one meter, which may be referred to asan “Initiate Node Scan Procedure” command. This command instructs thelevel one meter to perform its own node scan process. The requestcomprises several data items that the receiving meter may use incompleting the node scan. For example, the request may comprise thenumber of timeslots available for responding nodes, the unique addressof the collector that initiated the request, and a measure of thereliability of the communications between the target node and thecollector. As described below, the measure of reliability may beemployed during a process for identifying more reliable paths forpreviously registered nodes.

The meter that receives the Initiate Node Scan Response request respondsby performing a node scan process similar to that described above. Morespecifically, the meter broadcasts a request to which all unregisterednodes may respond. The request comprises the number of timeslotsavailable for responding nodes (which is used to set the period for thenode to wait for responses), the unique address of the collector thatinitiated the node scan procedure, a measure of the reliability of thecommunications between the sending node and the collector (which may beused in the process of determining whether a meter's path may beswitched as described below), the level within the subnet of the nodesending the request, and an RSSI threshold (which may also be used inthe process of determining whether a registered meter's path may beswitched). The meter issuing the node scan request then waits for andreceives responses from unregistered nodes. For each response, the meterstores in memory the unique identifier of the responding meter. Thisinformation is then transmitted to the collector.

For each unregistered meter that responded to the node scan issued bythe level one meter, the collector attempts again to determine thereliability of the communication path to that meter. In one embodiment,the collector sends a “Qualify Nodes Procedure” command to the level onenode which instructs the level one node to transmit a predeterminednumber of additional packets to the potential level two node and torecord the number of acknowledgements received back from the potentiallevel two node. This qualification score (e.g., 8 out of 10) is thentransmitted back to the collector, which again compares the score to aqualification threshold. In other embodiments, other measures of thecommunications reliability may be provided, such as an RSSI value.

If the qualification threshold is not met, then the collector adds anentry for the node in the Straggler Table, as discussed above. However,if there already is an entry in the Straggler Table for the node, thecollector will update that entry only if the qualification score forthis node scan procedure is better than the recorded qualification scorefrom the prior node scan that resulted in an entry for the node.

If the qualification threshold is met or exceeded, the collector 116registers the node. Again, registering a meter 114 at level twocomprises updating a list of the registered nodes at collector 116. Forexample, the list may be updated to identify the meter's uniqueidentifier and the level of the meter in the subnet. Additionally, thecollector's 116 registration information is updated to reflect that themeter 114 from which the scan process was initiated is identified as arepeater (or parent) for the newly registered node. The registrationprocess further comprises transmitting information to the newlyregistered meter as well as the meter that will serve as a repeater forthe newly added node. For example, the node that issued the node scanresponse request is updated to identify that it operates as a repeaterand, if it was previously registered as a repeater, increments a dataitem identifying the number of nodes for which it serves as a repeater.Thereafter, collector 116 forwards to the newly registered meter anindication that it is registered, an identification of the collector 116with which it is registered, the level the meter exists at in thesubnet, and the unique identifier of the node that will serve as itsparent, or repeater, when it communicates with the collector 116.

The collector then performs the same qualification procedure for eachother potential level two node that responded to the level one node'snode scan request. Once that process is completed for the first levelone node, the collector initiates the same procedure at each other levelone node until the process of qualifying and registering level two nodeshas been completed at each level one node. Once the node scan procedurehas been performed by each level one node, resulting in a number oflevel two nodes being registered with the collector, the collector willthen send the Initiate Node Scan Response command to each level twonode, in turn. Each level two node will then perform the same node scanprocedure as performed by the level one nodes, potentially resulting inthe registration of a number of level three nodes. The process is thenperformed at each successive node, until a maximum number of levels isreached (e.g., seven levels) or no unregistered nodes are left in thesubnet.

It will be appreciated that in the present embodiment, during thequalification process for a given node at a given level, the collectorqualifies the last “hop” only. For example, if an unregistered noderesponds to a node scan request from a level four node, and therefore,becomes a potential level five node, the qualification score for thatnode is based on the reliability of communications between the levelfour node and the potential level five node (i.e., packets transmittedby the level four node versus acknowledgments received from thepotential level five node), not based on any measure of the reliabilityof the communications over the full path from the collector to thepotential level five node. In other embodiments, of course, thequalification score could be based on the full communication path.

At some point, each meter will have an established communication path tothe collector which will be either a direct path (i.e., level one nodes)or an indirect path through one or more intermediate nodes that serve asrepeaters. If during operation of the network, a meter registered inthis manner fails to perform adequately, it may be assigned a differentpath or possibly to a different collector as described below.

As previously mentioned, a full node scan may be performed when acollector 116 is first introduced to a network. At the conclusion of thefull node scan, a collector 116 will have registered a set of meters 114with which it communicates and reads metering data. Full node scansmight be periodically performed by an installed collector to identifynew meters 114 that have been brought on-line since the last node scanand to allow registered meters to switch to a different path.

In addition to the full node scan, collector 116 may also perform aprocess of scanning specific meters 114 in the subnet 120, which isreferred to as a “node scan retry.” For example, collector 116 may issuea specific request to a meter 114 to perform a node scan outside of afull node scan when on a previous attempt to scan the node, thecollector 116 was unable to confirm that the particular meter 114received the node scan request. Also, a collector 116 may request a nodescan retry of a meter 114 when during the course of a full node scan thecollector 116 was unable to read the node scan data from the meter 114.Similarly, a node scan retry will be performed when an exceptionprocedure requesting an immediate node scan is received from a meter114.

The system 110 also automatically reconfigures to accommodate a newmeter 114 that may be added. More particularly, the system identifiesthat the new meter has begun operating and identifies a path to acollector 116 that will become responsible for collecting the meteringdata. Specifically, the new meter will broadcast an indication that itis unregistered. In one embodiment, this broadcast might be, forexample, embedded in, or relayed as part of a request for an update ofthe real time as described above. The broadcast will be received at oneof the registered meters 114 in proximity to the meter that isattempting to register. The registered meter 114 forwards the time tothe meter that is attempting to register. The registered node alsotransmits an exception request to its collector 116 requesting that thecollector 116 implement a node scan, which presumably will locate andregister the new meter. The collector 116 then transmits a request thatthe registered node perform a node scan. The registered node willperform the node scan, during which it requests that all unregisterednodes respond. Presumably, the newly added, unregistered meter willrespond to the node scan. When it does, the collector will then attemptto qualify and then register the new node in the same manner asdescribed above.

Once a communication path between the collector and a meter isestablished, the meter can begin transmitting its meter data to thecollector and the collector can transmit data and instructions to themeter. As mentioned above, data is transmitted in packets. “Outbound”packets are packets transmitted from the collector to a meter at a givenlevel. In one embodiment, outbound packets contain the following fields,but other fields may also be included:

-   Length—the length of the packet;-   SrcAddr—source address—in this case, the ID of the collector;-   DestAddr—the LAN ID of the meter to which the packet addressed;    -   RptPath—the communication path to the destination meter (i.e.,        the list of identifiers of each repeater in the path from the        collector to the destination node); and    -   Data—the payload of the packet.        The packet may also include integrity check information (e.g.,        CRC), a pad to fill-out unused portions of the packet and other        control information. When the packet is transmitted from the        collector, it will only be forwarded on to the destination meter        by those repeater meters whose identifiers appear in the RptPath        field. Other meters that may receive the packet, but that are        not listed in the path identified in the RptPath field will not        repeat the packet.

“Inbound” packets are packets transmitted from a meter at a given levelto the collector. In one embodiment, inbound packets contain thefollowing fields, but other fields may also be included:

-   Length—the length of the packet;-   SrcAddr—source address—the address of the meter that initiated the    packet;-   DestAddr—the ID of the collector to which the packet is to be    transmitted;    -   RptAddr—the ID of the parent node that serves as the next        repeater for the sending node;    -   Data—the payload of the packet;        Because each meter knows the identifier of its parent node        (i.e., the node in the next lower level that serves as a        repeater for the present node), an inbound packet need only        identify who is the next parent. When a node receives an inbound        packet, it checks to see if the RptAddr matches its own        identifier. If not, it discards the packet. If so, it knows that        it is supposed to forward the packet on toward the collector.        The node will then replace the RptAddr field with the identifier        of its own parent and will then transmit the packet so that its        parent will receive it. This process will continue through each        repeater at each successive level until the packet reaches the        collector.

For example, suppose a meter at level three initiates transmission of apacket destined for its collector. The level three node will insert inthe RptAddr field of the inbound packet the identifier of the level twonode that serves as a repeater for the level three node. The level threenode will then transmit the packet. Several level two nodes may receivethe packet, but only the level two node having an identifier thatmatches the identifier in the RptAddr field of the packet willacknowledge it. The other will discard it. When the level two node withthe matching identifier receives the packet, it will replace the RptAddrfield of the packet with the identifier of the level one packet thatserves as a repeater for that level two packet, and the level two packetwill then transmit the packet. This time, the level one node having theidentifier that matches the RptAddr field will receive the packet. Thelevel one node will insert the identifier of the collector in theRptAddr field and will transmit the packet. The collector will thenreceive the packet to complete the transmission.

A collector 116 periodically retrieves meter data from the meters thatare registered with it. For example, meter data may be retrieved from ameter every 4 hours. Where there is a problem with reading the meterdata on the regularly scheduled interval, the collector will try to readthe data again before the next regularly scheduled interval.Nevertheless, there may be instances wherein the collector 116 is unableto read metering data from a particular meter 114 for a prolonged periodof time. The meters 114 store an indication of when they are read bytheir collector 116 and keep track of the time since their data has lastbeen collected by the collector 116. If the length of time since thelast reading exceeds a defined threshold, such as for example, 18 hours,presumably a problem has arisen in the communication path between theparticular meter 114 and the collector 116. Accordingly, the meter 114changes its status to that of an unregistered meter and attempts tolocate a new path to a collector 116 via the process described above fora new node. Thus, the exemplary system is operable to reconfigure itselfto address inadequacies in the system.

In some instances, while a collector 116 may be able to retrieve datafrom a registered meter 114 occasionally, the level of success inreading the meter may be inadequate. For example, if a collector 116attempts to read meter data from a meter 114 every 4 hours but is ableto read the data, for example, only 70 percent of the time or less, itmay be desirable to find a more reliable path for reading the data fromthat particular meter. Where the frequency of reading data from a meter114 falls below a desired success level, the collector 116 transmits amessage to the meter 114 to respond to node scans going forward. Themeter 114 remains registered but will respond to node scans in the samemanner as an unregistered node as described above. In other embodiments,all registered meters may be permitted to respond to node scans, but ameter will only respond to a node scan if the path to the collectorthrough the meter that issued the node scan is shorter (i.e., less hops)than the meter's current path to the collector. A lesser number of hopsis assumed to provide a more reliable communication path than a longerpath. A node scan request always identifies the level of the node thattransmits the request, and using that information, an already registerednode that is permitted to respond to node scans can determine if apotential new path to the collector through the node that issued thenode scan is shorter than the node's current path to the collector.

If an already registered meter 114 responds to a node scan procedure,the collector 116 recognizes the response as originating from aregistered meter but that by re-registering the meter with the node thatissued the node scan, the collector may be able to switch the meter to anew, more reliable path. The collector 116 may verify that the RSSIvalue of the node scan response exceeds an established threshold. If itdoes not, the potential new path will be rejected. However, if the RSSIthreshold is met, the collector 116 will request that the node thatissued the node scan perform the qualification process described above(i.e., send a predetermined number of packets to the node and count thenumber of acknowledgements received). If the resulting qualificationscore satisfies a threshold, then the collector will register the nodewith the new path. The registration process comprises updating thecollector 116 and meter 114 with data identifying the new repeater (i.e.the node that issued the node scan) with which the updated node will nowcommunicate. Additionally, if the repeater has not previously performedthe operation of a repeater, the repeater would need to be updated toidentify that it is a repeater. Likewise, the repeater with which themeter previously communicated is updated to identify that it is nolonger a repeater for the particular meter 114. In other embodiments,the threshold determination with respect to the RSSI value may beomitted. In such embodiments, only the qualification of the last “hop”(i.e., sending a predetermined number of packets to the node andcounting the number of acknowledgements received) will be performed todetermine whether to accept or reject the new path.

In some instances, a more reliable communication path for a meter mayexist through a collector other than that with which the meter isregistered. A meter may automatically recognize the existence of themore reliable communication path, switch collectors, and notify theprevious collector that the change has taken place. The process ofswitching the registration of a meter from a first collector to a secondcollector begins when a registered meter 114 receives a node scanrequest from a collector 116 other than the one with which the meter ispresently registered. Typically, a registered meter 114 does not respondto node scan requests. However, if the request is likely to result in amore reliable transmission path, even a registered meter may respond.Accordingly, the meter determines if the new collector offers apotentially more reliable transmission path. For example, the meter 114may determine if the path to the potential new collector 116 comprisesfewer hops than the path to the collector with which the meter isregistered. If not, the path may not be more reliable and the meter 114will not respond to the node scan. The meter 114 might also determine ifthe RSSI of the node scan packet exceeds an RSSI threshold identified inthe node scan information. If so, the new collector may offer a morereliable transmission path for meter data. If not, the transmission pathmay not be acceptable and the meter may not respond. Additionally, ifthe reliability of communication between the potential new collector andthe repeater that would service the meter meets a threshold establishedwhen the repeater was registered with its existing collector, thecommunication path to the new collector may be more reliable. If thereliability does not exceed this threshold, however, the meter 114 doesnot respond to the node scan.

If it is determined that the path to the new collector may be betterthan the path to its existing collector, the meter 114 responds to thenode scan. Included in the response is information regarding any nodesfor which the particular meter may operate as a repeater. For example,the response might identify the number of nodes for which the meterserves as a repeater.

The collector 116 then determines if it has the capacity to service themeter and any meters for which it operates as a repeater. If not, thecollector 116 does not respond to the meter that is attempting to changecollectors. If, however, the collector 116 determines that it hascapacity to service the meter 114, the collector 116 stores registrationinformation about the meter 114. The collector 116 then transmits aregistration command to meter 114. The meter 114 updates itsregistration data to identify that it is now registered with the newcollector. The collector 116 then communicates instructions to the meter114 to initiate a node scan request. Nodes that are unregistered, orthat had previously used meter 114 as a repeater respond to the requestto identify themselves to collector 116. The collector registers thesenodes as is described above in connection with registering newmeters/nodes.

Under some circumstances it may be necessary to change a collector. Forexample, a collector may be malfunctioning and need to be takenoff-line. Accordingly, a new communication path must be provided forcollecting meter data from the meters serviced by the particularcollector. The process of replacing a collector is performed bybroadcasting a message to unregister, usually from a replacementcollector, to all of the meters that are registered with the collectorthat is being removed from service. In one embodiment, registered metersmay be programmed to only respond to commands from the collector withwhich they are registered. Accordingly, the command to unregister maycomprise the unique identifier of the collector that is being replaced.In response to the command to unregister, the meters begin to operate asunregistered meters and respond to node scan requests. To allow theunregistered command to propagate through the subnet, when a nodereceives the command it will not unregister immediately, but ratherremain registered for a defined period, which may be referred to as the“Time to Live”. During this time to live period, the nodes continue torespond to application layer and immediate retries allowing theunregistration command to propagate to all nodes in the subnet.Ultimately, the meters register with the replacement collector using theprocedure described above.

One of collector's 116 main responsibilities within subnet 120 is toretrieve metering data from meters 114. In one embodiment, collector 116has as a goal to obtain at least one successful read of the meteringdata per day from each node in its subnet. Collector 116 attempts toretrieve the data from all nodes in its subnet 120 at a configurableperiodicity. For example, collector 116 may be configured to attempt toretrieve metering data from meters 114 in its subnet 120 once every 4hours. In greater detail, in one embodiment, the data collection processbegins with the collector 116 identifying one of the meters 114 in itssubnet 120. For example, collector 116 may review a list of registerednodes and identify one for reading. The collector 116 then communicatesa command to the particular meter 114 that it forward its metering datato the collector 116. If the meter reading is successful and the data isreceived at collector 116, the collector 116 determines if there areother meters that have not been read during the present reading session.If so, processing continues. However, if all of the meters 114 in subnet120 have been read, the collector waits a defined length of time, suchas, for example, 4 hours, before attempting another read.

If during a read of a particular meter, the meter data is not receivedat collector 116, the collector 116 begins a retry procedure wherein itattempts to retry the data read from the particular meter. Collector 116continues to attempt to read the data from the node until either thedata is read or the next subnet reading takes place. In an embodiment,collector 116 attempts to read the data every 60 minutes. Thus, whereina subnet reading is taken every 4 hours, collector 116 may issue threeretries between subnet readings.

Meters 114 are often two-way meters—i.e. they are operable to bothreceive and transmit data. However, one-way meters that are operableonly to transmit and not receive data may also be deployed. FIG. 4 is ablock diagram illustrating a subnet 401 that includes a number ofone-way meters 451-456. As shown, meters 114 a-k are two-way devices. Inthis example, the two-way meters 114 a-k operate in the exemplary mannerdescribed above, such that each meter has a communication path to thecollector 116 that is either a direct path (e.g., meters 114 a and 114 bhave a direct path to the collector 116) or an indirect path through oneor more intermediate meters that serve as repeaters. For example, meter114 h has a path to the collector through, in sequence, intermediatemeters 114 d and 114 b. In this example embodiment, when a one-way meter(e.g., meter 451) broadcasts its usage data, the data may be received atone or more two-way meters that are in proximity to the one-way meter(e.g., two-way meters 114 f and 114 g). In one embodiment, the data fromthe one-way meter is stored in each two-way meter that receives it, andthe data is designated in those two-way meters as having been receivedfrom the one-way meter. At some point, the data from the one-way meteris communicated, by each two-way meter that received it, to thecollector 116. For example, when the collector reads the two-way meterdata, it recognizes the existence of meter data from the one-way meterand reads it as well. After the data from the one-way meter has beenread, it is removed from memory.

While the collection of data from one-way meters by the collector hasbeen described above in the context of a network of two-way meters 114that operate in the manner described in connection with the embodimentsdescribed above, it is understood that the present invention is notlimited to the particular form of network established and utilized bythe meters 114 to transmit data to the collector. Rather, the presentinvention may be used in the context of any network topology in which aplurality of two-way communication nodes are capable of transmittingdata and of having that data propagated through the network of nodes tothe collector.

Techniques are disclosed herein for providing wireless networkcommunication nodes with opt-out capabilities. Such capabilities may,for example, allow particular customers to opt out of a typicalfull-scale communication mode such that their associated equipmentoperates at least temporarily in a limited communication mode. Thelimited communication mode may limit customer exposure to emissionsresulting from RF communications near their homes or other areas, whichmay be attractive to customers such as those with health or otheremission-related concerns.

In addition to customer concerns, one or more nodes may be configured tooperate in a limited communication mode for any appropriate reason. Theterm “limited communication mode” is used herein to refer to a mode,configuration and/or other operational setting in which a node isscheduled or configured to communicate less frequently than when thesame and/or other network nodes are not operating in the limitedcommunication mode. The term “limited communication node” will refer toa communication node that is operating in the limited communicationmode. Also, the term “full-scale communication mode” is used herein torefer to an operational mode for a communication node that is notoperating in a limited communication mode. Also, the term “full-scalecommunication node” will refer to a communication node that is notoperating in the limited communication mode. As should be appreciated,the operating mode of some or all of the communication nodes may bere-configurable such that they may be switched between a limitedcommunication mode and the full-scale communication mode any number oftimes for any appropriate reasons.

In some embodiments, to limit RF communications emissions, a limitedcommunication node's transceiver may be powered off during periods whenthe communication node isn't transmitting its associated data. Acommunication node's associated data may include, for example, meteringdata or any other appropriate data associated with the node. As setforth above, a communication node's transceiver may include, forexample, a radio and/or cellular modem or any other appropriatetransceiver functionality. Thus, the communication node hardware may beprovided with the ability to disconnect power from the transceiver whilestill allowing other node functionality to remain operational. Forexample, if the communication node includes metering functionality, thenthe node may be provided with the ability to continue to operate itsmetering functionality while the transceiver is powered off.Additionally, the communication node software and/or firmware may beprovided with the ability to power on and power off the communicationnode transceiver as desired.

In some cases, the normal operating state of a limited communicationnode may be to have its transceiver powered off. The node softwareand/or firmware may include a schedule that powers on the transceiver atcertain times. The power on times may occur, for example, at certaintimes of the day, month, year and/or any other appropriate repeating ornon-repeating interval or time. In some cases, a local clock or timerrunning locally at the communication node may be used in conjunctionwith a schedule in order to trigger the transceiver to be powered on.The transceiver power on schedule may be configurable remotely fromanother network node and/or via local direct connection at acommunication node. As an example, the schedule may be configuredremotely from a central node or another connected computer or otherdevice. The remote node may have a matching schedule with which thecommunication node's local schedule can be synchronized when the remotenode communicates with the communication node.

In some example scenarios, when a limited communication node'stransceiver functionality is powered on, a modem may establish awireless/cellular connection to other system nodes using, for example, aprivate wireless network or a public cellular network. Once thewireless/cellular connection is established, the node may have theoption of pushing its current associated data, such as meter measurementdata, to other system nodes or allowing other system nodes topoll/retrieve the node's current associated data.

After being powered up, the transceiver may remain on for anyappropriate time. In some cases, there may be a parameter that controlsa maximum amount of time that a limited communication node's transceiverremains active without receiving a communication. If no communicationsare received within this time period, then the transceiver may send amessage to other system nodes stating that node is disconnecting fromthe network. The node's transceiver may then be powered off.

In the event of an AC or other power failure, a limited communicationnode may have the capability of powering up its transceiver and sendingan outage notification message to other system nodes. When power isrestored to the limited communication node, it may have the capabilityof powering up its transceiver and sending a power restoration messageafter which the transceiver may be powered off.

In some example cases, opt out capabilities may be provided in wirelessmesh networks that do not require tight time or frequencysynchronization of endpoints for successful communications. In some suchexample networks, communications may be achieved in a self-coherentfashion, meaning that a communication is transmitted by an endpoint ordata collection point without regard for the time or the frequency ofthe endpoint. When a transmission occurs, a remote endpoint may scan allchannels in the mesh network looking for the transmitted channel. Whenthe transmitted channel is found (based on, for example, high RSSI andvalid preamble) the message may be decoded on the fly. Thisself-coherency or self-synchronization concept may, for example, allowany endpoint to receive any communication at any time without anaccurate clock and without cumbersome network communications for tightsynchronization. These example characteristics may be advantageous whena given endpoint is not communicating for a significant period of timesuch as when operating in the limited communication mode.

Additionally, in some example cases, opt out capabilities may beprovided in wireless mesh networks that build out from a collector inmultiple hop levels such as some example wireless networks describedabove. Such networks may achieve strong communications with endpointrepeaters. Additionally, in some example scenarios, some or allcommunication nodes may be capable of serving as repeaters and thenetwork may find high performance paths through these various repeatersto build out a successful communication network.

These example wireless networks and other wireless networks may employ aconfiguration parameter that causes a new communication path to bedetermined for a communication node when the communication node has notbeen in communication with the network within a specified threshold timeperiod. This threshold time period is referred to herein as a “brokenpath time.” As an example, a collector may cause a new communicationpath to be determined when the collector fails to receive any indicationthat a communication node has transmitted any data within the brokenpath time. The broken path time may be employed, for example, in orderto re-route communications when a repeater in an existing communicationpath has become inoperative. As an example, in some networks, a defaultbroken path time may be set to 18 hours.

Limited communication nodes may, in some cases, not transmit theirassociated data for intervals that are much longer than the defaultbroken path time. In such cases, however, it may not be desirable togenerate a new communication path for the limited communication nodesimply because the node is not scheduled to transmit its data. Accordingto an aspect of the present disclosure, techniques may be employed suchthat the broken path time may be selectively extended for limitedcommunication nodes. Such an extension of the broken path time may allowthe limited communication nodes to transmit their associated data atless frequent intervals without the need to determine a newcommunication path during periods when the limited communication nodeisn't transmitting. As an example, in some networks, a default brokenpath time for limited communication nodes could be set to 45 days. Thismay allow, for example, a limited communication node to register andthen be activated once a month (or via some other random, infrequentschedule) so a trip to the site would not have to be achieved.

As set forth above, certain networks may include communication nodesthat are capable of serving as repeaters. However, in some cases,limited communication nodes may be prohibited from serving as arepeater, even when the nodes would otherwise be capable of serving asrepeaters when not in the limited communication mode. For example, aparticular node could serve as a repeater while operating in thefull-scale communication mode. Then, upon being switched to the limitedcommunication mode, that same node could be temporarily prohibited fromserving as a repeater as long as it continues to operate in the limitedcommunication mode. Such a restriction could significantly reduce thetransmissions performed by that node while operating in the limitedcommunication mode.

A number of examples are described above in which a limitedcommunication node's transceiver is “normally” powered off with theexception of certain times at which the node is transmitting itsassociated data. However, in some other cases, a limited communicationnode may have its transceiver remain powered up during all orsubstantial portions of time while operating in the limitedcommunication mode. This may, for example, allow a limited communicationnode to remain capable of receiving information such as clock and/ortimer information and read requests. Additionally, for example, this mayallow a limited communication node to issue various messages such as anAC or other power outage alert without the need to first power up thetransceiver.

To support the opt out scenario, a central node (e.g., gatekeeper,collector) may have separate reading schedules for limited communicationnodes. A node can be designated for operation in the limitedcommunication mode using, for example, a system interface (e.g.,“pushed” down from a head end server or other device) or via directconfiguration of the communication node (e.g., via the optical port orother interface at the communication node). Communication nodes may alsobe switched out of the limited communication mode using similarinterfaces. When a meter is designated for operation in the limitedcommunication mode, several configuration parameters in the meter can bechanged to control the extent to which communication will be limited.

Some example reconfigurable parameters for limited the communicationmode may include limiting and/or disabling of messages that areinitiated by the communication node, which are referred to herein as“exception messages.” In some cases, to more strictly limitcommunications, exception messages for limited communication nodes maybe fully disabled. In other cases, one or more filters may be used toidentify only a limited set of exception message that are available foruse in the limited communication mode. As an example, exception messagesmay be limited to only critical events, such as outage and restoration.

Some other example reconfigurable parameters may include limiting thetypes of requests to which a limited communication node is permitted torespond. For example, limited communication nodes may be prohibited fromresponding to node scan requests, but may be permitted to respond todata read requests from the meter's registered gatekeeper.

Another example reconfigurable parameter may include, as set forthabove, extending the broken path time for limited communication nodes toa higher value (e.g., 45 days) than for other full-scale communicationnodes (e.g., 18 hours).

In some example wireless networks, one or more central nodes (e.g.,gatekeepers, collectors) may be primarily responsible for assigningand/or maintaining communication paths for communication nodes in thenetwork. As set forth above, such communication paths to a central nodemay include a number of intermediate relay or repeater nodes. In somecases, for a limited communication node, in addition to a selected(i.e., “primary”) communication path, the central node may also maintainadditional communication paths to the collector through other neighbornodes that are one communication hop from the limited communicationnode. In some cases, depending upon the number of existing neighbors, atleast one or two additional communication paths may be maintained. Suchadditional communication paths may, for example, be identified toprovide additional robustness for the infrequent communication with thelimited communication node, thereby helping to ensure that suchcommunication may be maintained through changes in communicationperformance or changes in network structure (e.g., nodes removed fromthe network). For example, when the central node attempts to read datafrom a limited communication node, if a primary communication path is nolonger effective, then one of the additional communication paths may beemployed in order to read data from the limited communication node.

In some cases, a central node may employ a separate set of schedules(“limited communication schedules”) to specify the limited readoperations for the designated limited communication nodes. For example,a central node may be configured to read limited communication nodesonly once a month, where the once a month read can be performed on aspecified billing date for each of the limited communication nodes. Thecentral node may attempt communications to a limited communication nodevia the identified neighbor nodes, stopping communication attempts whena response is received or communications have been attempted through allidentified neighbors.

As set forth above, in some cases, limited communication nodes may beprohibited from serving as repeaters. This may be true even when thelimited communication node would otherwise be capable of serving as arepeater when operating in a full-scale communication node. FIGS. 5A and5B depict an example scenario in which a repeater node is switched fromoperation in a full-scale communication mode to operation in a limitedcommunication mode. In particular, FIG. 5A depicts an example scenarioin which transmit-only or one-way nodes 553 and 554 have two separatecommunication paths to collector 116. Specifically, node 553 has acommunication path through bi-directional or two-way nodes 514 a, 514 cand 514 e, while node 554 has a communication path through two-way nodes514 b, 514 d and 514 f. All of the two-way nodes 514 a-f in FIG. 5A areoperating in a normal full-scale communication mode.

FIG. 5B depicts an example scenario in which node 514 f is switched intothe limited communication node. The operation of node 514 f in thelimited communication node is shown by the thick black circlesurrounding node 514 f. The remaining two-way nodes 514 a-e continue tooperate in the in the normal full-scale communication mode. Node 514 fis prohibited from serving as a repeater while it operates as in thelimited communication mode. Thus, node 514 f has been removed from thecommunication path of node 554. Instead, as shown in FIG. 5B, node 554has its communication path re-routed through nodes 514 a, 514 c and 514e. As should be appreciated, if it is later switched back to thefull-scale communication mode, then node 514 f may once again bepermitted to serve as a repeater.

Thus, a number of example characteristics such as those described abovemay be applicable with respect to limited communication nodes. Someexample procedures for applying such characteristics will now bedescribed. In particular, FIG. 6 depicts a flowchart of an examplelimited communication node configuration process. The process of FIG. 6may be performed by, for example, any combination of a communicationnode, a central node such as a collector or gatekeeper, a connectedcomputing device for managing network communications and/or any otherappropriate device. As should be appreciated, any number of the actsdepicted in FIG. 6 may be optional, and the acts depicted in FIG. 6 maybe performed in any appropriate order. Additionally, any combination ofthe acts depicted in FIG. 6 may be combined together such that areperformed collectively as part of a single act or step.

At act 610, an indication is received that a first communication node isdesignated for operation in the limited communication node. As set forthabove, a communication node can be designated for operation in thelimited communication mode using, for example, a system interface (e.g.,“pushed” down from a head end server or other device) or via directconfiguration of the communication node (e.g., via the optical port orother interface at the communication node). A notification of thisdesignation may also be transmitted to other nodes or devices other thanthe device that is used to initially make the designation. For example,an indication of a designation made at a head end server may be “pushed”down to other network nodes. Also, an indication of a designation madeat the first communication node may be reported upstream to othernetwork nodes.

In response to its designation as a limited communication node, thefirst communication node may be designated as prohibited from serving asa repeater at act 612. This designation may, for example, be generatedand/or maintained by any one or more of the first communication node, acentral node such as a collector or gatekeeper, a connected computingdevice for managing network communications and/or any other appropriatedevice. As should be appreciated, if any other communication nodes havecommunication paths that include the first communication node as arepeater, then the designation of act 612 may result in a need tore-route those other communication nodes (for example, as depicted inFIGS. 5A and 5B and described above). As should also be appreciated, insome cases, the first communication node may be prohibited from or maybe incapable of serving as a repeater even when operating in the fullscale communication node. In such cases, act 612 may be unnecessary asthe first communication node may already be designated as prohibitedfrom or incapable of serving as a repeater.

At act 614, the first communication node may be associated with areduced frequency schedule for transmitting its associated data. Suchassociated data may include, for example, meter measurement data. Thefrequency of the transmissions may be reduced in comparison to thefrequency at which one or more other nodes in operating in the fullscale communication node transmit their associated data. As describedabove, the reduced frequency communication schedule may, for example, beset and/or maintained using any one or more of the first communicationnode, a central node such as a collector or gatekeeper, a connectedcomputing device for managing network communications and/or any otherappropriate device. For example, the first communication node may storea reduced frequency schedule of times at which to power on itstransceiver to transmit its associated data. As another example, acentral node may store a reduced frequency schedule of times at which toinitiate a read of each limited communication node, and the firstcommunication node may be added to this reduced frequency schedule.

At act 616, a broken path time associated with the first communicationnode may be extended. As described above, when no network transmissionis received from a particular communication node within the broken pathtime, then a new communication path may be determined for thatparticular node. As an example, in some networks, a default broken pathtime may be set to 18 hours. Limited communication nodes may, in somecases, not transmit their associated data for intervals that are muchlonger than the default broken path time. Thus, the broken path time maybe selectively extended for limited communication nodes to a longervalue (e.g., 45 days). Such an extension of the broken path time mayallow the limited communication nodes to transmit their associated dataat less frequent intervals without the need to determine a newcommunication path during periods when the limited communication nodeisn't transmitting.

At act 618, additional communication paths may be determined for thefirst communication node. As described above, the additionalcommunication paths may, for example, provide additional robustness forinfrequent communication with a limited communication node, therebyhelping to ensure that such communication may be maintained throughchanges in communication performance or changes in network structure.

At act 620, the first communication node may be restricted to a limitedset of messages types that it is permitted to initiate. Messagesinitiated by a communication node are referred to herein as “exceptionmessages.” As described above, in some cases, to more strictly limitcommunications, exception messages for limited communication nodes maybe fully disabled. In other cases, one or more filters may be used toidentify only a limited set of exception message that are available foruse in the limited communication mode. As an example, exception messagesmay be limited to only critical events, such as outage and restoration.

At act 622, the first communication node may be restricted to limitedset of messages types to which it is permitted to respond. For example,limited communication nodes may be prohibited from responding to nodescan requests, but may be permitted to respond to data read requestsfrom the meter's registered gatekeeper.

Any number of additional or alternative acts may also be performed inassociation with the example process depicted in FIG. 6. For example, asdescribed above, in some cases, the first communication mode may beconfigured such that its transceiver is typically powered off and isonly powered on at scheduled times in order to transmit the node'sassociated data.

In some cases, a central node or other connected computer or device maymaintain settings for configuration of limited communication nodes. Insuch cases, when a node is designated as a limited communication node,the maintained limited communication node settings may automatically beapplied to the limited communication node without the need to separatelydetermine and identify each of the settings. Even in such cases,however, settings for certain limited communication may be adjusted asdesired such that settings for all limited communication nodes need notbe completely identical.

As should be appreciated, each node operating in the limitedcommunication mode may be configured differently with differentcharacteristics, schedules, settings and/or other parameters. In othercases, each node operating in the limited communication mode may befully or partially configured with the same or similar characteristics,schedules, settings and/or other parameters. Additionally, any number ofdifferent limited communication modes with some different respectivecharacteristics, schedules, settings and/or other parameters may beemployed within a single network or multiple networks.

All or portions of the subject matter disclosed herein may be embodiedin hardware, software, or a combination of both. When embodied insoftware, the methods and apparatus of the subject matter disclosedherein, or certain aspects or portions thereof, may be embodied in theform of program code (e.g., computer executable instructions). Thisprogram code may be stored on a computer-readable medium, such as amagnetic, electrical, or optical storage medium, including withoutlimitation, a floppy diskette, CD-ROM, CD-RW, DVD-ROM, DVD-RAM, magnetictape, flash memory, hard disk drive, or any other machine-readablestorage medium, wherein, when the program code is loaded into andexecuted by a machine, such as a computer or server, the machine becomesan apparatus for practicing the invention. A device on which the programcode executes will generally include a processor, a storage mediumreadable by the processor (including volatile and non-volatile memoryand/or storage elements), at least one input device, and at least oneoutput device. The program code may be implemented in a high levelprocedural or object oriented programming language. Alternatively, theprogram code can be implemented in an assembly or machine language. Inany case, the language may be a compiled or interpreted language. Whenimplemented on a general-purpose processor, the program code may combinewith the processor to provide a unique apparatus that operatesanalogously to specific logic circuits.

While systems and methods have been described and illustrated withreference to specific embodiments, those skilled in the art willrecognize that modification and variations may be made without departingfrom the principles described above and set forth in the followingclaims. Accordingly, reference should be made to the following claims asdescribing the scope of the present invention.

What is claimed is:
 1. A method for wireless network operationcomprising: receiving an indication that a first communication node isdesignated for operation in a limited communication mode, wherein thefirst communication node is included in a wireless network comprising acentral node and a plurality of communication nodes in wirelesscommunication with the central node, each of the communication nodeshaving a wireless communication path to the central node that is eithera direct path or an indirect path through one or more intermediatecommunication nodes serving as relays, wherein one or more of thecommunication nodes operate in the limited communication mode in whichthey are scheduled to transmit data less frequently than one or moreother communication nodes not operating in the limited communicationmode; and scheduling reading of data from the first communication nodeto be performed less frequently than reading of data from the one ormore other communication nodes not operating in the limitedcommunication mode, wherein, for each of the one or more othercommunication nodes not operating in the limited communication mode,when the central node does not receive an indication that thecommunication node has performed a network transmission within a firstthreshold time period, the central node causes a new wirelesscommunication path to be determined for the communication node, wherein,for the first communication node, when the central node does not receivean indication that the first communication node has performed a networktransmission within a second threshold time period, the central nodecauses a new wireless communication path to be determined for the firstcommunication node, and wherein the first threshold time period isshorter than the second threshold time period.
 2. The method of claim 1,further comprising designating the first communication node as beingprohibited from serving as a relay while operating in the limitedcommunication mode.
 3. The method of claim 1, further comprisingreceiving an indication that the first communication node is no longerdesignated for operation in the limited communication mode.
 4. Themethod of claim 1, wherein the central node maintains a first scheduleand a second schedule, wherein the first schedule indicates a firstfrequency of times at which to read data from the one or more othercommunication nodes not operating in the limited communication mode,wherein the second schedule indicates a second frequency of times atwhich to read data from the one or more communication nodes operating inthe limited communication mode, wherein the first frequency is morefrequent than the second frequency, and wherein the first communicationnode is associated with the second schedule.
 5. The method of claim 1,further comprising associating the first communication node with aschedule that indicates times at which to power up a transceiver of thefirst communication node.
 6. The method of claim 1, wherein the firstcommunication node is configured to allow its transceiver to remainpowered on while operating in the limited communication mode.
 7. Themethod of claim 1, further comprising attempting to determine one ormore additional communication paths from the first communication node tothe central node.
 8. The method of claim 1, further comprising causingthe first communication node to be configured to respond to fewer typesof requests than the one or more other communication nodes not operatingin the limited communication mode.
 9. The method of claim 1, furthercomprising causing the first communication node to be configured totransmit fewer types of messages than the one or more othercommunication nodes not operating in the limited communication mode. 10.A wireless network comprising: a central node; and a plurality ofcommunication nodes in wireless communication with the central node,each of the communication nodes having a wireless communication path tothe central node that is either a direct path or an indirect paththrough one or more intermediate communication nodes serving as relays,wherein one or more of the communication nodes operate in a limitedcommunication mode in which they are scheduled to transmit data lessfrequently than one or more other communication nodes not operating inthe limited communication mode, wherein, for each of the one or moreother communication nodes not operating in the limited communicationmode, when the central node does not receive an indication that thecommunication node has performed a network transmission within a firstthreshold time period, the central node causes a new wirelesscommunication path to be determined for the communication node, andwherein, for each communication node operating in the limitedcommunication mode, when the central node does not receive an indicationthat the communication node has performed a network transmission withina second threshold time period, the central node causes a new wirelesscommunication path to be determined for the communication node, andwherein the first threshold time period is shorter than the secondthreshold time period.
 11. The wireless network of claim 10, wherein atleast one of the communication nodes is reconfigurable to be switchedinto and out of operation in the limited communication mode.
 12. Thewireless network of claim 10, wherein the central node maintains a firstschedule and a second schedule, wherein the first schedule indicates afirst frequency of times at which to read data from the one or moreother communication nodes not operating in the limited communicationmode, wherein the second schedule indicates a second frequency of timesat which to read data from the one or more communication nodes operatingin the limited communication mode, wherein the first frequency is morefrequent than the second frequency.
 13. The wireless network of claim10, wherein at least one of the communication nodes operating in thelimited communication mode has an associated schedule that indicatestimes at which to power up a transceiver.
 14. The wireless network ofclaim 10, wherein, for each communication node operating in the limitedcommunication mode, the central node determines the wirelesscommunication path for the central node and also attempts to determineone or more additional communication paths from the communication nodeto the central node.
 15. The wireless network of claim 10, wherein atleast one of the communication nodes operating in the limitedcommunication mode is configured to allow its transceiver to remainpowered on throughout a duration of its operation in the limitedcommunication mode.
 16. The wireless network of claim 10, wherein thecommunication nodes operating in the limited communication mode areprohibited from serving as relays.
 17. The wireless network of claim 10,wherein the communication nodes operating in the limited communicationmode are configured to respond to fewer types of requests than the oneor more other communication nodes not operating in the limitedcommunication mode.
 18. The wireless network of claim 10, wherein thecommunication nodes operating in the limited communication mode areconfigured to transmit fewer types of messages than the one or moreother communication nodes not operating in the limited communicationmode.
 19. The wireless network of claim 10, wherein the communicationnodes operating in the limited communication mode are configured torespond only to read requests.
 20. A non-transitory computer-readablestorage medium having stored thereon instructions that, upon executionby one or more processors, cause the one or more processors to performoperations comprising: receiving an indication that a firstcommunication node is designated for operation in a limitedcommunication mode, wherein the first communication node is included ina wireless network comprising a central node and a plurality ofcommunication nodes in wireless communication with the central node,each of the communication nodes having a wireless communication path tothe central node that is either a direct path or an indirect paththrough one or more intermediate communication nodes serving as relays,wherein one or more of the communication nodes operate in the limitedcommunication mode in which they are scheduled to transmit data lessfrequently than one or more other communication nodes not operating inthe limited communication mode; and scheduling reading of data from thefirst communication node to be performed less frequently than reading ofdata from the one or more other communication nodes not operating in thelimited communication mode, wherein, for each of the one or more othercommunication nodes not operating in the limited communication mode,when the central node does not receive an indication that thecommunication node has performed a network transmission within a firstthreshold time period, the central node causes a new wirelesscommunication path to be determined for the communication node, wherein,for the first communication node, when the central node does not receivean indication that the first communication node has performed a networktransmission within a second threshold time period, the central nodecauses a new wireless communication path to be determined for the firstcommunication node, and wherein the first threshold time period isshorter than the second threshold time period.